Method of applying closures to containers



Nov. 7, 1944. f `E. E. `Horas I METHOD 0F APPLYING CLOSURES` TO CONTAINERS Filed Aug. 2, 1940 xNvr-:NToR- Zine/"5017 Ef Hogg Y i BY ('ffr RNEY Patented Nov. 7, 1944 i mamon or Ammo cLosUnEs 'ro communs Emerson E. Hogg, New Kensington, Pa.. assignor to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania Application August 2, 1940, serial No. 349,745

(ci. 22e-s0) '4 Claims.

This invention relates to a method of uniting closures with containers.

In the closure industry, a type of metal cap, J

often identified as a snap-on or pry-oi! cap, has been known for years. These caps are retained by inwardly disposed projections that cooperate with a suitable bead on the container, the number and size of such projections being such that the cap skirt can be exed to. a shape permiting passage of the projections past the container bead. The comercial success of preformed snap-on or pry-oft' caps has beenretarded by Fig.` 1 is a view of the cap in elevation before aiiixation to a container;

Fig. 2 is an enlarged view in elevation or the Y cap secured to a suitable container;

variations in the sealing characteristics ofthe r caps. Many do not provide an hermetic seal,

and many, on the other hand, areso tightly applied that they can only be removed by strenuous eilorts. These disadvantages result mainly from variations in the dimensions of both caps and container finishes that are unavoidable in large volume production of caps and containers.

To eliminate these disadvantages attending the use of preformed snap-on or pry-G caps, it has been suggested that theretaining projections or lugs be formed in the cap skirt above the usual bottom bead or wire edge when the cap is in sea-ling position on the container. However, this suggestion, to the best of my knowledge, has been made only in connection with caps of relatively deep skirts and containers with small necks and relatively high compressive strengths.

Accordingly, it is an object of this invention to provide a package with a cap' of the pry-oil' type which is assured of hermetic sealing properties regardless of whether the package -is of the vacuum type or must maintain internal pressures greater than atmospheric. It is a further obiect to providean easily opened and re-usable package in which the retaining lugs oi' the cap are located in the-wire edge, and are tailor-made ject is the provision of a novel method .of seali ing to accomplish the foregoing objects in which Fig. 3 is an enlarged sectional view taken on the line III-III of Fig. 2;

Fig. 4 is an enlarged sectional view of a fragment of the cap and container before' sealing;

Fig. 5 is an enlarged sectional-elevational view of he cmp and container showing the manner of maintaining the cap in sealing position for amxation; and

Fig. 6 is an enlarged view illustrative of the method provided by this invention lfor forming the securing lugs.

With reference now to Figs. 1, 2, and 3 in particular; the cap III comprises a Quei-piece, shallow sheet metal shell ci the gauges customarily usedfor caps, having a depressed top center vpanel il, an initially flat peripheral top portion I2, and a continuous skirt i3, terminating in an outwardly turned wire edge i4.- Carried within the annular channel formed by the depressed centerrpanel Il and peripheral portion i2 is a resilient sealing gasket l5, which is preferably made of a relatively plastic rubber formulation in a flat ring-like shape. The skirt may'be knurled, if desired, to provide corrugations.

To alx the cap l0 to a suitable container I1, a number of indentations or lugs I8 are formed from the wire edge I l in a manner hereinafter described. The number, shape, and size of the lugs are immaterial so long as they permit the cap skirt to 'flex under' pry-oil pressure to a polygonalshape that allows passage of the container mouth without permanent deformation' the cap is maintained after amxation in a stressed condition resistant to deformation. v The manner .in which these objects are obtained, together with their attendant advantages,

y will Abe better understood from the following detailed description of the invention with reference to the drawing, in which:

of the lugs. However, the lugs are also preferably of 'such number that they are uniformly spaced circumferentially and of such a size that the larger dimension extends circumferentially of the wire edge. But it is recognized that the lugs for some lpurposes may be created in series of two or more relatively small slightlyI .tions of that part of the bead lying outwardly of the uppermost part of the mouth rim is of consequence to my invention. With respect to this segment of the bead 20, it is necessary that the upper portion 2| be divergent from the crest of the bead to permit the peripheral cap portion I2 and gasket I5 to be deflected or wrapped about it as shown in Figs. 2, 3, 5, and 6. It is likewise essential that the aforesaid outer segment of the glass bead 20 be provided with a surface 22 that converges downwardly from a diameter equal to the maximum outside container diameter through the bead, and of suitable angularity radius to permit proper grip or hook of the lugs I8 thereon. Preferably, however, the surface 22 is provided with a convex, cross-sectional contour. Thus, although this invention is particularhr adaptable wardly the portion I2 and compresses the sealing gasket I5 tolower the wire edge I4 into position forI formation of the lugs I8. This position is one that is determined by the amount of hook or grip of the lugs on the bead portion 22 that is required by the type of package being produced,

' it being obvious that a vacuumized package will to the sealing of containers having relatively small arcuate mouth beads such as the socalled safety edge and chipless beads, the mouth bead may be of varying cross-sectional shapes so long as the above-mentioned conditions are maintained.

It will be appreciated by those skilled in the art that the inevitable variations in dimensions of both caps and containers make it a difficult problem to provide suci'ent hook of the lugs I8 on the bead portion 22 to-as'sure an hermetic seal and also acceptable characteristics of removability that permit preservation of the general shape of the cap and lugs for reclosure purposes. This Iproblem of satisfactory afllxation is made even more troublesome by the fact that neither the pressure applied to the top of the cap to create the seal by compression of the sealing gasket, nor the pressureappli'ed to form the lugs, can, as a practical matter, be adjusted to accommodate the dimensional variations of each cap and container to assure |the position of the wire edge Il and the degree of indentation of that wire edge, that make possible the formation of lugs that grip the container bead in the optimum manner.

I have found that the creation of a stressed condition in the cap shell during the formation of the lugs and the subsequent maintenance thereof will provide the necessary factor of dimensional accommodation. This stressed condition is induced by applying sealing pressure to the top of a cap of suitable skirt length in such a manner that not only is the sealing gasket coml pressed and wrapped about the top bead portion 2|, but the peripheral cap portion I2 is also similarly wrapped or deflected prior to formation of the lugs I8. This wrapping or deflection of the cap, together with the compression of the gasket,

' to removal of external top pressure.

produces at each of the subsequently formed lugs a C clamp of a self-maintained nature on radial planes extending through the lugs. The maintenance of this stressed condition of the cap subsequent to ailixation is materially assisted by the depressed center panel] I, which resists the tendency of the cap to bow or arch across the entire diameter when the peripheral portion I2 is deflected.

that lowering of the pressure block exes dOWnrequire less hook than one maintaining internal pressures greater than atmospheric. In any event, the position should be one in which the entire wire edge, as shown in Fig. 5, is appreciably below the line A-B, which is the horizontal plane of juncture of the bead,portion 22 with the portion thereabove.

While the cap is maintained in the aforedescribed position and condition, the desired number of lugs I8 equally spaced are formed by pressure applied inwardly against the wire edge It by a like number of pressure elements, such as those fragmentarily shown in Fig. 6 and identified by the reference numeral 26. The pressure elements 26 are preferably yieldably applied and simultaneously actuated. The lugs produced by such local deformation of the wire edge in the direction of and against the container will then grip the surface of the previously juxtaposed convergent bead portion 22, since they are formed primarily by lateral transposition of the wire edge.

`It has been my experience with this manner of cap aiixation that the top peripheral portion I2 between lugs I8 has a tendency, under some circumstances, to arch or bow upwardly subsequent This, of course, tends to lift the wire edge intermediate the lugs, which portions in addition are likely to expand outwardly. These conditions may be produced by excessive top pressure, and they are naturally aggravated inpackages having internal pressures greater than atmospheric after the time of sealing. These tendencies toward deformation may also be a result of the reactive force generated by the local deformation of the wire edge I4 to form the lugs I8. Regardless of the cause or causes, I consider it highly desirable to prevent the occurrence of these conditions or tendencies since they lead to the production of leakers or non-hermetic packages.

To prevent occurrence of the aforedescribed conditions I have found that portions of the wire edge intermediate the lug areas should have pressure maintained thereagainst during formation of the lugs which will tend to deflect such portions downwardly and that confinement of the cap skirt portion against radial expansion is likewise desirable. The amount of pressure applied to such intermediate portions for this purpose may vary, depending upon whether a pronounced downward bow of the intermediate wire edge portions is desired, or merely a slight deflection suflicient to reinforce the aiilxed cap against peripheral arching of the top surface in the opposite direction is sought. This manner of creating resistance to top bowing or arching depends, for the most part, on the fact that formation of the lugs, during the existence of'the deflecting pressure against the intermediate wire edge portions, tends to give the deflected intermediate portions a permanent set whether or not the elastic limit of the wire edge is exceeded by the deflection. since the lugs prevent circumferential distribution of the deflection throughout the entire wire edge.

A convenient manner of providing this latter phase of my preferred manner of aixation of `lugs, asshown in Fig. 5. Suitable openings 29 between the legs 21 permit free access of the pressure elements 2S to the wire edge, as is illustrated in Fig. 6." The desired coninement of the cap skirt is easily secured by making Ythe diameter across the legs 21' such that the recess so formed is only large enough receive .the cap skirt I3 exclusive of the wire edge M.- Thus, the package is assured of an ainxed cap that will retain its desired shape when the pressure block is removed.

It is apparent that the cap III aiiixed to the container I1, as illustrated in Fig. 2 by the manner illustrated by Figs. 4, 5, and 6, is removable in the same manner as a preformed snap-on cap ot conventional design. In other words, the cap is removable upon application of 'pressure upwardly against the wire edge I4 in order to ilex the cap skirt sumciently to permit the lugs I8 to ride over the container bead 2l. It will also be realized that any cap so iitted to a particular con- I' tainer can be readily 're-applied for temporary reclosure of the container in the manner ofthe ordinary snap-on cap.

I wish it to be understood that. although the provision of a shallow-skirted lug type of pry-of! cap in combination withalI thin glass tumbler is .an important phase of my invention, the invention is in no way so limited; accordingly, withthc intent to include all modiiications and embodiments of this invention that come within the scope and spirit of the appended claims, I claim-z l. In a method of amxing a cap including a' .resilient sealing gasket and a cup-like shell terminating in a beaded edge to a container having an annular mouth bead comprising a portion out .wardly divergent from the crest of the mouth rim and a portion convergent towards the body portion of the container, the steps comprising dedecting both said shell and said sealing gasket about said divergent bead portion by pressure applied against the top of said shell, applying pressure downwardly against a plurality of portions of said beaded edge, and. while maintaining said pressures. deforniing said beaded edge inwardly at a plurality of points intermediate the aforesaid stressed beaded edge portions to form .hiss Slipping said convergent bead portion.

llnamethodvofami'xingacapincludin'ga resilient sealing gasket and a cup-like shell terminating in an outwardly turned beaded edge to a container having an annular mouth bead comprising a portion outwardly divergent from the crest of the mouth rim and a convex portion converging towards the body portion of the container, the steps comprising deflecting both said shell and said sealing gasket about said divergent l bead portion by pressure applied to the peripheral top portion of said shell, bowing downwardly a plurality of uniformly spaced portions of said beaded edge, and, while maintaining said deiiected and bowed conditions, deforming .said

beaded edge inwardly at a plurality of points inV termediate the aforesaid bowed beaded edge portions to form lugs gripping said convex bead portion.

3. In a method of aiiixing a cap including' a resilient sealing gasket and a cup-like shell terminating in an outwardly turned beaded edge to a container having an annular mouth bead comprising a portion outwardly divergent from the crest of the mouth rim and a convex portion convergent towards the body portion of the con tainer, said steps comprising deiiecting both said shell and saidV sealing gasket about said'divergent bead portion, applying pressure downwardly against a plurality ci uniformly spaced portions of said beaded edge, confining the skirt of said cap against radial expansion, and, while maintaining siid pressures and said coniined condition, deforming said beaded edge inwardly at a plurality of pointsV intermediate the aforesaid stressedbeaded edge portions to form lugs gripping said convex bead portion.

4. In a method of alxing a cap including a resilient sealing gasket and a shallow cup-like metal shell terminating inwan outwardly turned beaded edge to a thin glass tumbler having a continuous mouth bead consisting of a convex portion outwardly divergent from the crest of the mouth rim and adjoining said portion aI convex portion convergent towards the body portion oi the tumbler, said stepscomprising deiiecting both said shell and said sealing gasket about said divergent bead portion, applying pressure downwardly against a plurality oi uniformly spaced r inn-.noaa 

